Gas turbine engines are incorporated in a wide range of vehicles such as airplanes, rotary-wing aircraft, and land vehicles. During operation of these vehicles, air is continuously being drawn into the gas turbine engine from an outer periphery of the vehicle. The air will then mix with fuel and combust to rotate the engine and turn a transmission or gearbox.
The operating nature of rotary-wing aircraft subjects the gas turbine engine to a wide range of conditions that can cause particles of various sizes to become airborne in the vicinity of the rotary-wing aircraft and be drawn in with air intended to enter the gas turbine engine. This is particularly true when operating a rotary-wing aircraft in a sandy dessert environment as the movement of the rotors can cause the formation of sand clouds. Because sand melts and forms glass at normal operating temperatures for the gas turbine engine, it is important to prevent sand from entering the engine and covering internal components and clogging cooling passages. Therefore, there is a need to prevent particles from entering portions of a gas turbine engine that operate at temperatures above the melting point of sand.